In the past, with development of a high-density multi-core cable that stores a single mode optical fiber tape of, for example, four cores, eight cores, and twelve cores, a multi-core batch connector capable of efficiently connecting an optical fiber at a high density has been used as a connector for collectively connecting an SM-type optical fiber single-core wire and a tape core wire with low loss. This connection scheme is a scheme in which ferrules formed by positioning and fixing a multi-core optical fiber are aligned and fitted to each other by two guide pins. The connector is applicable to high-speed mechanical switching in addition to batch connection of the optical fiber tape, and thus is referred to as an MT connector. Recently, the connector has been put to practical use as a connector for connection of an optical fiber tape of four cores, eight cores, and twelve cores of a multi-core cable of an access system.
In addition, recently, an MPO connector, which is easily attached and detached by a push-pull operation, has been put to practical use as a batch connector of multiple cores of 24 cores and 72 cores for connection of a super-multi-core cable.
Specifically, as disclosed in Patent Document 1, it is known that an MT connector or a so-called MPO connector, in which a connection surface is tilted and polished and an optical fiber slightly protrudes, is used as a multi-core connector, a reinforcement member is embedded in a longitudinal direction of a main body of a ferrule, and the main body of the ferrule is prevented from bending in the longitudinal direction by the reinforcement member.
In addition, as disclosed in Patent Document 2, it is known that a ferrule of an optical connector using a scheme, in which a fiber hole is present in a front end portion and positioning is performed with respect to a ferrule on the other side by a fitting pin inserted into a guide pin hole, is formed by combining a connection end portion corresponding to a component including the fiber hole and the guide pin hole with a main body rear portion corresponding to a component other than the connection end portion.
As illustrated in FIG. 6(a) and FIG. 6(b), each of the above-described connectors of Patent Document 1 and Patent Document 2 includes an adhesive filling window 101 on an upper surface of a main body 100 of a ferrule, a pair of right and left guide pin insertion holes 102 for positioning penetrating through the main body 100 of the ferrule from a front end surface to a rear end surface, and a plurality of optical fiber core wire insertion holes 103 arranged in parallel between both the guide pin insertion holes 102 on the front end surface. Further, the connector includes an insertion opening portion 104 for insertion and support of a boot (not illustrated) on the rear end surface of the main body 100 of the ferrule, and a flange 105 extruding outward from an outer peripheral surface of the main body 100 of the ferrule on a rear end side of the main body 100 of the ferrule.